Over the years a great deal of progress has been achieved in providing new and improved fluid absorbing media in items such as diapers, sanitary napkins, incontinent garments and industrial spill absorbing ropes, pigs, and the like.
The following U.S. patents disclose various types of fluid and liquid absorbing devices. DePhillips, U.S. Pat. No. 2,527,299 discloses a water impermeable sheet material which is capable of passing vapors therethrough. Hoey U.S. Pat. No. 3,901,240 discloses a permeable polymeric liner on an absorbent pad of foam which disintegrates upon flushing in a sewage system. Kemp U.S. Pat. No. 3,953,638 discloses a multi-ply, absorbent, wiping product having a relatively inextensible inner ply that is bonded to highly extensible outer plys. Burkholder Jr. U.S. Pat. No. 3,959,569 discloses a process for preparing water absorbent articles such as bandages and absorbent pads.
Hoey U.S. Pat. No. 4,069,366 discloses a permeable polymeric liner for absorbent pad used in sanitary napkins, wound dressings and the like. Holst, et al. U.S. Pat. No. 4,200,558 discloses a process for producing hydrophilic articles from water insoluble polymers. Erickson U.S. Pat. No. 4,293,609 discloses a flexible absorbent laminate made from a crushed film of lightly cross-linked or water soluble hydrophilic polymers. Fowler U.S. Pat. No. 4,372,309 discloses a moisture absorbent pad of wood pulp impregnated with a starch polymer or an acrylic based polymer and useful in absorbing liquid wastes such as urine and the like.
Wahlquist, et al. U.S. Pat. No. 4,379,192 discloses a nonwoven, melt blown, absorbent barrier fabric useful in hospitals, such as surgical drapes and the like. Dehnel U.S. Pat. No. 4,392,908 discloses a process for making water-absorbent articles having water-soluble polymers fixed to a water-absorbent substrate. Dawn, et al. U.S. Pat. No. 4,411,660 discloses an absorbent product for body wastes such as urine and fecal matter employing multiple layers of material for passing and absorbing fluids and liquids, and having a layer for contact with the skin which is leak-proof. Michaels U.S. Pat. No. 4,223,061 discloses an internal body drug dispenser using liquid swellable material to expand and disperse the drug.
Korpman U.S. Pat. No. 4,449,977 discloses a flexible, non-disintegrative, absorbent product having a water-insoluble, non-swelling matrix. Haq, et al. U.S. Pat. No. 4,603,069 discloses a sheet-like article for wiping hard surfaces and the like having an inner layer of liquid absorbing material and bonded together with spot welds between outer sheets. McFarland, et al. U.S. Pat. No. 4,604,313 discloses a fabric-like material containing melt blown material and wood fibers deposited on a foraminous belt. Ness U.S. Pat. No. 4,629,457 discloses an absorbent facing material and method for making the same having a significant one-way valve characteristic for aqueous fluids. Ito, et al. U.S. Pat. No. 4,364,992, discloses a two-layer absorbent article having a super-water-absorbing polymer. Duncan U.S. Pat. No. 4,701,369 discloses an opaque, polymer film laminate having an absorbent surface for absorbing and containing liquids, and Duncan U.S. Pat. No. 4,702,954 discloses an opaque, barrier layer capable of transmitting a vapor therethrough.
McCabe U.S. Pat. No. 4,124,116 discloses a liquid-absorbing enclosure containing absorbent granules surrounded by a filter paper and a dissolvable paper sealed together along the outermost edges. The Cullen, et al. U.S. Pat. No. 4,749,600 teaches water-absorbent pouches containing water-soluble outer covering material.
One aspect of the present invention is to provide a new and improved pouch for absorbing fluids and more particularly to provide a new and improved pouch for absorbing and containing aqueous fluids leaking from packaging, shipping containers and the like during shipment and/or storage.
Another aspect of the present invention is to provide a new and improved pouch of the character described which is especially well adapted for absorbing body fluids, urine, fecal matter, blood and other aqueous body wastes and contaminants in a highly efficient manner to preclude contamination and damage to the immediate environment should liquid leakage occur.
Another aspect of the present invention is to provide a new and improved low cost, highly absorbent pouch of the character described which is resistant to rupture when dry, and is capable of absorbing large quantities of liquid much in excess of the weight and unswollen volume of the pouch itself and easily rupturable, when wetted, to allow the absorbent material to expand beyond the outermost periphery of the pouch.
Still another aspect of the present invention is to provide a new and improved pouch of the character described which will allow for the internal water-absorbing material to break through an outer paper material after absorbing a high volume of liquid.
A further aspect of the present invention is to provide a new and improved pouch of the character described that encapsulates a water-swellable, water-absorbent material, e.g., super-absorbent polymer, between paper or fabric sheet material layers, wherein edges of the pouch are sealed together such that upon expansion of the water-absorbent material, one or more of the seams will separate (delaminate) to permit the material to spread outwardly from the pouch in a desired direction or in a plurality of directions.
Another aspect of the present invention is to provide a new and improved pouch of the character described which is relatively low in cost and yet still capable of absorbing many times its own volume and weight in aqueous liquids.